Everyone is familiar with Tetra Brik juice containers. These are the rectangular juice boxes with a straw on the side and a tinfoil spot on the top through which you punch the straw. This packaging is supplied world-wide by Tetra Pak, a well-known packaging machinery company.
The major producer of Tetra Brik beverages in Saudi Arabia is Binzagr Co-Ro Ltd., headquartered in Jeddah. Not long ago we did some very interesting testing for them.
Binzagr fills millions of these per day, and 1% may be rejected during start-up, transitions between flavors, CIP, etc.
Initially the goal was to separate the liquid from reject containers, using a single machine. This meant that we needed to achieve shredding action as well as squeezing forces. A twin screw press would have been good for this, but it was ruled out because of its cost.
A relatively inexpensive Model KP-10 press was modified for the task. Shearing action was achieved with a combination of strippers, cord cutters, and resistor teeth. In addition the screw was machined to an undersize diameter so that packaging material would not pinch and co-rotate with the screw.
A load of 4,000 Tetra Briks was used in the testing, and the results were outstanding. However fiber contaminants in the juice precluded salvage of the juice. Tetra Brik boxes have six layers of paper, poly, and tinfoil. That must be poly on both sides of the paper and tinfoil. It turned out that we could find no way of keeping torn paper, cellophane, and tinfoil particles from getting into the juice. In the end the client reverted to our original recommendation, a screw compactor built by our European distributor, RUNI.
In & Out Results